Carbapenem until susceptibility known, then step down to fluoroquinolone, cotrimoxazole, or aminoglycoside.

Do not treat with cephalosporins as may induce resistance.

Piperacillin-tazobactam may be considered in select cases where:
-Isolate is susceptible
-Patient not critically ill or immunocompromised
-Short duration therapy
-Tissue concentration high (biliary or urinary infections)